DESCRIPTION (Verbatim from Applicant's Abstract): The long term goal of this project is to develop a high resolution cone beam volume computed tomography (CBVCT) imaging technique to provide clinically useful three-dimensional (3D) high resolution images for thoracic oncologic imaging. CBVCT uses a cone beam geometry and a newly developed digital flat panel detector for fast volume scanning. It will require only a single fast volume scanning (2 - 8.0 seconds) to provide true 3D description of pulmonary anatomy with 0.7 - 4.0 lp/mm isotropic resolution. CBVCT represents the next step in the evolution in CT. Rapid acquisition will eliminate most motion artifacts. Sub-millimeter isotropic resolution should detect more pulmonary nodules, virtually eliminating partial volume average artifacts. CBVCT should allow for the first time accurate determination of size, growth, density, and enhancement characteristics of small pulmonary nodules. This would be a major advance in oncologic pulmonary imaging. CBVCT will be developed and validated through computer simulation, phantom and animal studies performed on a prototype imaging system that uses a thin film transistor (TFT) flat panel detector and cone beam tomographic acquisition geometry. Specifically, the aims of the proposed research are: 1) Develop and validate data acquisition technique for TFT array-based CBVCT through computer simulation, 2) Develop, implement and optimize the cone beam reconstruction algorithms, 3) Construct a TFT-based prototype CBVCT scanner, 4) Test and optimize the CBVCT technique through phantom studies, and 5) Evaluate imaging performance of the CBVCT system through comparison phantom studies with a multi-slice CT. Animal studies will be prepared upon the successful completion of this proposed research.